As an example of a mobile communication system to which the present invention is applicable, a 3rd Generation Partnership Project Long Term Evolution (hereinafter, “LTE”) and LTE-Advanced (hereinafter, “LTE-A”) communication system is described in brief.
FIG. 1 is a diagram schematically showing a network structure of an E-UMTS as an exemplary mobile communication system.
Referring to FIG. 1, an Evolved Universal Mobile Telecommunications System (E-UMTS) is an advanced version of a conventional Universal Mobile Telecommunications System (UMTS) and basic standardization thereof is currently underway in the 3GPP. E-UMTS may be generally referred to as a Long Term Evolution (LTE) system. For details of the technical specifications of the UMTS and E-UMTS, reference can be made to Release 7 and Release 8 of “3rd Generation Partnership Project; Technical Specification Group Radio Access Network”.
Referring to FIG. 1, the E-UMTS includes a User Equipment (UE), eNode Bs (eNBs), and an Access Gateway (AG) which is located at an end of the network (E-UTRAN) and connected to an external network. The eNBs may simultaneously transmit multiple data streams for a broadcast service, a multicast service, and/or a unicast service.
One or more cells may exist in one eNB. A cell is set to use one of bandwidths of 1.25, 2.5, 5, 10, and 20 MHz to provide a downlink or uplink transport service to several UEs. Different cells may be set to provide different bandwidths. The eNB controls data transmission and reception for a plurality of UEs. The eNB transmits downlink scheduling information with respect to downlink data to notify a corresponding UE of a time/frequency domain in which data is to be transmitted, coding, data size, and Hybrid Automatic Repeat and reQuest (HARQ)-related information. In addition, the eNB transmits uplink scheduling information with respect to uplink data to a corresponding UE to inform the UE of an available time/frequency domain, coding, data size, and HARQ-related information. An interface for transmitting user traffic or control traffic may be used between eNBs. A Core Network (CN) may include the AG, a network node for user registration of the UE, and the like. The AG manages mobility of a UE on a Tracking Area (TA) basis, wherein one TA includes a plurality of cells.
Although radio communication technology has been developed up to LTE based on Wideband Code Division Multiple Access (WCDMA), demands and expectations of users and providers continue to increase. In addition, since other radio access technologies continue to be developed, new technical evolution is required to secure future competitiveness. Decrease of cost per bit, increase of service availability, flexible use of a frequency band, simple structure, open interface, and suitable power consumption by a UE are required.
Recently, 3GPP has been establishing a standard task for a subsequent technique of LTE. In this specification, such a technique is referred to as “LTE-A”. One of the main differences between an LTE system and an LTE-A system is system bandwidth and the introduction of a Relay Node (RN). The LTE-A system is aimed at supporting a broadband of a maximum of 100 MHz and, to this end, the LTE-A system is designed to use a carrier aggregation or bandwidth aggregation technique using a plurality of frequency blocks. Carrier aggregation employs a plurality of frequency blocks as one large logical frequency band in order to use a wider frequency band. A bandwidth of each frequency block may be defined based on a bandwidth of a system block used in the LTE system. Each frequency block is transmitted using a component carrier.
As described above, in the LTE-A system introducing the RN, research into resource allocation for transmitting control information for the RN and resource allocation for transmitting system information (or broadcast information) for the RN has not been conducted. In addition, a specific method in which an eNB signals control information for the RN and resource allocation information for broadcast information transmission has not been proposed.
Furthermore, although it is necessary to know a start point of an R-PDSCH in order for the RN to perform decoding by successfully receiving signals and control information from the eNB, a specific method therefor has not been proposed.